Thx Tim
My dealer and myself apparently got our wires crossed and were looking at the incorrect engine specs. I revisited a Volvo Maintenance Service Doco and found the following for a B63x4x (T6) engine.
Aux belt/tensioner/idler pulley 240,000km or 10 years
Rubber connection generator 240,000km or 15years.
Appreciate you supplying the correct info, a big financial saving as I had been quoted over $2K to exchange the chain.